Adrenal gland- Quick revision card

Adrenal gland - Two adrenal glands just above each kidney Each weigh about 4-6 gm , 3 cm wide , 5 cm high and 1 cm thick Adrenal cortex is the outer part which makes about 90 % of the gland Adrenal medulla is the inner region & makes < 10 % of the gland.

Adrenal cortex - Steroidogenesis - produces precursors for glucocorticoids , mineralocorticoids and androgens Made of 3 layers○ zona glomerulosa the outermost layer ( Aldosterone )○ zona fasciculata middle layer ( Corticosteroids )○ zona reticularis innermost layer ( androgens ) Steroidogenesis is the complex pathway which leads to transform cholesterol into steroid hormones ACTH ( Adrenocorticotrophic hormone ) is the main hormone which regulates adrenal glucocorticoid biosynthesis and secretion.

Adrenal medulla - part of the autonomic nervous system activated by similar stimuli as the sympathetic nervous system as exercise , cold , stress , bleeding major cells are called chromaffin cells medulla secretes○ epinephrine ( 80 % )○ norepinephrine ( 19 % )○ dopamine ( 1 % ) Others- acetylcholine , metenkephalin , chromogranin A considered as part of the sympathetic NS and is innervated by cholinergic paraganglion sympathetic NS

Aldosterone - regulates plasma concentration of...